Physicians have a number of technologies they use to find the cause of pain. Primarily these include:

• Electrodiagnostic procedures
• electromyography (EMG)
• nerve conduction studies
• evoked potential (EP) studies.
• Information from EMG can help physicians tell precisely which muscles or nerves are affected by weakness or pain. Thin needles are inserted in muscles and a physician can see or listen to electrical signals displayed on an EMG machine.
• With nerve conduction studies the doctor uses two sets of electrodes (similar to those used during an electrocardiogram) that are placed on the skin over the muscles. The first set gives the patient a mild shock that stimulates the nerve that runs to that muscle. The second set of electrodes is used to make a recording of the nerve's electrical signals, and from this information the doctor can determine if there is nerve damage.
• EP tests also involve two sets of electrodes-one set for stimulating a nerve (these electrodes are attached to a limb) and another set on the scalp for recording the speed of nerve signal transmission to the brain.
• Imaging
• magnetic resonance imaging or MRI, provides physicians with pictures of the body's structures and tissues. MRI uses magnetic fields and radio waves to differentiate between healthy and diseased tissue.
• others
• A neurological examination in which the physician tests movement, reflexes, sensation, balance, and coordination.
• X-rays produce pictures of the body's structures, such as bones and joints.